Abstract
We present the spectroscopic confirmation of the brightest known gravitationally lensed Lyman-break galaxy in the Epoch of Reionization (EoR), A1703-zD1, through the detection of [C ii] 158 μm at a redshift of z = 6.8269 ± 0.0004. This source was selected behind the strong lensing cluster Abell 1703, with an intrinsic luminosity and a very blue Spitzer/Infrared Array Camera (IRAC) [3.6]-[4.5] colour, implying high equivalent width line emission of [O iii] + Hβ. [C ii] is reliably detected at 6.1σ cospatial with the rest-frame ultraviolet (UV) counterpart, showing similar spatial extent. Correcting for the lensing magnification, the [C ii] luminosity in A1703-zD1 is broadly consistent with the local L[C,II]-star formation rate (SFR) relation. We find a clear velocity gradient of 103 ± 22 km s-1 across the source that possibly indicates rotation or an ongoing merger. We furthermore present spectral scans with no detected [C ii] above 4.6σ in two unlensed Lyman-break galaxies in the Extended Groth Strip (EGS)-Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) field at z ∼6.6-6.9. This is the first time that the Northern Extended Millimeter Array (NOEMA) has been successfully used to observe [C ii] in a 'normal' star-forming galaxy at z > 6, and our results demonstrate its capability to complement the Atacama Large Millimeter/submillimeter Array (ALMA) in confirming galaxies in the EoR.
Original language | American English |
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Pages (from-to) | 535-543 |
Number of pages | 9 |
Journal | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY |
Volume | 512 |
Issue number | 1 |
DOIs | |
State | Published - 1 May 2022 |
Keywords
- galaxies: evolution
- galaxies: formation
- galaxies: high-redshift
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science